Lesson 5 - Chapter 1: Wireless Networking Basics Flashcards
Nearly all wireless networks these days operate using…?
radio frequencies
What standard is the most common type of wireless network today based on?
wireless networks today are based on the IEEE 802.11 wireless Ethernet standard (marketed as Wi-Fi)
What is a shorter-range technology used primarily to connect wireless peripherals to individual computing devices?
Bluetooth
(printers, headsets, mice, etc)
What does WMN stand for?
Wireless Mesh network
What is a WMN? How big is its range?
a small, limited-range network where each node acts like a router and forwards traffic for other nodes without wires
(can interconnect computers in deployed Army field units or between Google Home devices in an IoT network)
What 2 options do you have if a computer doesn’t have the needed wireless adapters?
- add a Wi-Fi PCIe card for a desktop PC
- add an external USB wireless NIC
Since a cell phone supports both cell and Wi-Fi networks, you can use your phone as a Wi-Fi WAP. What does this mean? What is it called? (2)
it uses the cellular connection to pass signals to/from the Internet
(you create a hotspot)
What is tethering? Using what device?
when you bridge an Internet connection to the cellular network
(using a cell phone)
Wi-Fi devices can communicate directly 1-1 with each other, but usually will have a central connecting device called…?
Wireless Access Point (WAP)
sometimes abbreviated to AP (Access Point)
What is a WAP? What does it do?
connects wireless network nodes into a wireless LAN (WLAN) just like a switch does with wired connections
(basically a wireless switch)
How is a WAP similar to a router?
WAPs can act as wireless routers, enabling networked computers to access outside networks (Internet)
In small networks, how are WAPs configured?
Usually manually by a tech using its built-in firmware
What are Wireless LAN controllers?
Useful for centralizing the process of configuring many WAPs (instead of doing it manually like for small networks)
How are Wireless LAN controllers configured? Where can you find it?
can use a single software interface to configure thousands of WAPs (with the interface hosted on a local computer, or in the cloud)
Cloud-based network controllers are referred to as?
cloud-managed WLANs
How do you configure a newly installed wireless network adapter?
There is very little to do as Windows recognizes it easily, they are plug-and-play but you do need to set parameters such as the network name
For the little settings you need to change for a wireless network adapter, what do you use?
Window’s built-in tools or software tool from the wireless network adapter vendor
Wireless networks use what 3 methods to secure access to the data in flight and the network itself?
- MAC address filtering
- Authentication
- Data Encryption
What does SSID stand for? What is it also called? (2)
service set identifier (SSID)
aka network name
WAPs are usually configured to broadcast their ___ to their maximum range
their SSID
Avoid leaving your SSID to its default. Why?
It gives away important clues about the manufacturer/model of your access point
What can you do if you don’t want the WAP’s SSID broadcasted?
disable SSID broadcasting
How would a device connect to a WAP with a hidden SSID?
the user needs to know the SSID’s name and be able to type it in
What’s a good location to place an omni-directional antenna?
in the center of the home/office, since the closer it is to a wall the more likely someone outside can get a wireless signal
Can you adjust the radio power levels of the antenna?
Yes, many WAPs enable you to adjust the antenna power levels
(adjust it so you can get reception inside target work place, not outside)
What is MAC address filtering?
(Best for a small number of users)
enables you to limit access to your wireless network based on the physical address of the (attempting) unit’s NIC
(can create a list of accepted users to limit access)
How does MAC address filtering work?
A table stored in the WAP lists the MAC addresses that are permitted to participate in the wireless network. Any data packets that don’t contain the MAC addresses listed in the table are rejected.
Wireless encryption protects the WAP in 2 ways:
- Prevents hosts from connecting to it without the right password
- Encrypts the transmissions so anyone who intercepts the data can’t read it
What does WEP stand for?
Wired Equivalent Privacy (early WiFi encryption, not secure)
What are the 4 Wireless Network Encryption standards?
- WEP (Wired Equivalent Privacy)
- WPA (Wi-Fi Protected Access)
- WPA2 (Wi-Fi Protected Access 2)
- WPA3
What does WPA stand for?
Wi-Fi Protected Access
-uses TKIP security protocol to provide new encryption key for every packet sent
-uses EAP for integrity and user authentication
What does TKIP stand for?
Temporal Key Integrity Protocol
What does EAP stand for?
Extensible Authentication Protocol
Which Wireless network encryption standard uses AES (Advanced Encryption Standard)?
WPA2 (Wi-Fi Protected Access 2)
What is the encryption strength of WEP, WPA, WPA2, and WPA3?
WEP = 40-bit, 104-bit
WPA = 128-bit
WPA2 = 128-bit
WPA3 = 192-bit
What does WPS stand for?
Wi-Fi Protected Setup
What is WPS used for?
a standard included on most WAPs to make secure connections easier to configure for inexperienced users
How does WPS work?
you either press a button or use a password/code on both devices to connect the two WPS-capable devices together
(press a button on a WPS-capable printer, then press the WPS button on the WAP to automatically configure a secure connection or WPS code on the device, enter it in Windows like a network password)
What’s a downside to having WPS enabled?
It’s very easy to hack, better to have it off
(a hacker can guess the 8 digit code printed on the WAP device to connect to the network)
Wireless networking bandwidth speeds depend on what 3 things?
- the networking standard
- distance between the node and WAP
- interference from solid objects/other wireless devices
Standard speeds can vary from ___ to ___
Standard speeds can range from a measly 2 Mbps to a snappy 1+ Gbps
(maximum throughput only achieved within around 25 feet)
Maximum throughput is only achieved within how many feet?
25 feet, then speed will slowly fall the further you are from it
What 3 things can create dead spots when it comes to effective network range?
- Walls
- Large objects (appliances)
- Wireless devices in the same frequency range (cordless phones, baby monitors, microwaves)
What are 4 ways you can increase wireless network range?
- Installing extra WAPs (that you can roam between)
- Replace stock antennas with higher-gain versions
- Use a signal booster
- Use wireless repeaters/extenders to receive/rebroadcast Wi-Fi signal
What standard defines methods that devices may use to communicate via radio waves?
the IEEE 802.11 wireless Ethernet standard
802.11-based wireless technologies broadcast and receive on one of which 2 radio bands?
- 2.4 GHz
- 5 GHz
What is a “band”?
a contiguous range of frequencies that is divided up into slices called channels
contiguous = next to each other, share a common border
What are channels?
the divided-up range of frequencies (bands)
Are newer wireless devices backward compatible with older ones?
(For example, 802.11n WAP with older 802.11g devices)
Yes, 802.11n WAP is compatible with older 802.11g devices.
Another example, 802.11ac BC with 802.11b, g, and n.
The only exception to backward compatibility with wireless devices is which 802.11 standard?
802.11a (2nd oldest) = requires a 5 GHz radio which makes only 802.11ac (5th newer) and dual-band 802.11n (4th place) WAPs backward compatible with “a” devices
What are the 6 wireless Ethernet standards? Name them by the order in which they came out
- 802.11b
- 802.11a
- 802.11g
- 802.11n
- 802.11ac
- 802.11ax
What is the band, throughput, and maximum range for each of the wireless network standards? (6)
- 802.11b = 2.4 GHz, 11 Mbps, <300 feet
- 802.11a = 5 GHz frequency range, 54 Mbps (25 Mbps normally), <150 feet
- 802.11g = 2.4 GHz band, 54 Mbps, <300 feet
- 802.11n = dual-band, 600 Mbps, <300 feet
- 802.11ac = 5 GHz band dual-band, 1.3 Gbps, <300 feet
- 802.11ax = dual-band, 14 Gbps, <300 feet
Which standard introduced MIMO? What does MIMO mean? (2)
- 802.11n, 802.11ac (Multiuser MIMO)
- MIMO - Multiple In, Multiple Out. Enables devices to make simultaneous connections with up to 4 antennas
What is transmit beamforming? What wireless standard employs it? (2)
Transmit beamforming is when the multiple antennas adjust the signal once the WAP discovers a client to help get rid of dead spots
the 802.11n standard employs it
What does OFDMA stand for?
Orthogonal Frequency-Division Multiple Access
What does OFDMA do? What standard is it a feature of?
a dual-band feature of the 802.11ax standard that provides 4x the throughput per device when there are multiple devices that need bandwidth (airports, schools)
4 streams in the 2.4 GHz band
8 streams in the 5 GHz band
What does NFC stand for?
Near Field Communication
How does NFC work?`
it’s a super short-range, low-power consumption technology that uses chips embedded in mobile devices to create electromagnetic fields when these devices are close to each other
(few centimeters to few inches range, must be close or touching)
What does RFID stand for?
Radio frequency identification
What is RFID used for? What is it used with?
it’s a wireless networking protocol used with asset tags to keep track of inventory
What is an asset tag?
it contains an RFID tag (microchip, antenna)
a RFID scanner/reader can read it even without line of sight to the item!
Where do passive RFID tags get their power from?
since they’re passive, they get their power from the scanner’s signal
Where do active RFID tags get their power from?
it uses a battery or external power source to send out/receive signals
Barcodes and RFID tags can always be updated with new details. T or F?
False, only RFID tag information can be updated
What is Bluetooth designed for?
creates small wireless networks to do very specific jobs (headsets, wearable technology, car audio)
What is PAN and what does it do?
Personal Area Network (PAN) uses Bluetooth tech to link 2 computers for a quick/dirty wireless network
(Bluetooth is not designed to be a full-function network solution or compete with Wi-Fi)
Instead of continuing to improve speed, what does the 4th generation (4.0, 4.1, 4.2) of of Bluetooth focus on? (4)
With what kind of devices?
focused on improving Bluetooth’s cost, power consumption, speed/security, and introducing IP connectivity with networked “smart” devices/appliances
What is spread-spectrum? What does this make it resistant to?
broadcasts data in small, discrete chunks over the frequencies available in a certain range (highly resistant to interference)
What’s the difference between WiFi and Bluetooth’s broadcasting method?
Wi-Fi uses fixed frequency, Bluetooth uses spread spectrum (data chunks hop certain frequencies in a range 1600 times a second)
Bluetooth devices are classified in what 3 classes that define maximum power usage? What are the speeds and max distance? (3)
- Class 1 - 100 mW - 100 meters
- Class 2 - 2.5 mW - 10 meters
- Class 3 - 1 mW - 1 meter
What is Bluetooth’s maximum power usage measured in?
milliwatts (mW)
What are 2 office uses for Bluetooth?
- Acceptable for quick file transfers if wired connections or a faster wireless connection is unavailable
- Its speed and range make it a good match for wireless print server solutions
What are 2 ways Bluetooth is built-in or added in?
- Built into gadgets
- Adapter added to internal/external expansion bus
